Location, timing, and mobility: Understanding a parasitoid guild in fragmented agricultural landscapes

This study examines the parasitoid guild of sunflower moth, Homoeosoma electellum (LEPIDOPTERA: PYRALIDAE), a native specialist herbivore and serious pest of crop sunflower (Helianthus annuus L.) at the local habitat (crop vs. self seeding), landscape, and population level.  At each scale, we examine factors that impact parasitism parameters such as overall parasitism rates, parasitoid species richness, and the relative roles of specialist and generalist parasitoids.   Through the use of sentinel larvae experiments, G.I.S. analysis of surrounding landscape matrix, and a population genetics analysis using microsatellite markers, we explore the spatial and temporal factors that influence the parasitoids of this important pest species in the Great Central Valley of California.  Habitat type, proximity to orchards (versus annual crops) and riparian habitat are correlated with parasitism parameters.  We discuss the relative merits of using habitat, landscape and population level tools to understand and eventually manage for natural enemies of native pest species in fragmented agricultural landscapes.